It is often necessary to examine manufactured and in particular filled containers for specific defects, for example for the presence of shards of glass within the container or for the presence of contaminants. For this purpose the containers to be examined run through these inspection devices and it is ascertained whether specific defects are present. However, it is also necessary to examine the precision of such inspection plants. For this purpose original containers are used and they are provided with a test contaminant. If the inspection device recognises this container, it may be assumed that the inspection device is working properly. However, the problem of such containers is that the containers wear relatively quickly, since the product located therein is contaminated with germs. These can multiply phenomenally in most beverages and thus make the test container unusable. If unfilled containers are used, the test results are often less significant, above all because the index of refraction of the liquid essentially necessitates different optical arrangements than empty containers.
Furthermore in the past the outputs are permanently increased and so also the throughput of containers per unit of time. If the test containers are filled with a product which is particularly attractive for consumption, such as for example alcoholic beverages and other premium products, there is a danger that such a test container will pass through the inspection device and will no longer be recognised later.